My Jack Dempsey is the most beautiful fish to me. Originally, I kept it with my pacu, green terror and ornate bichir but I transferred the Jack Dempsey and green terror to the cichlids tank. It is not as aggressive as I thought it would be, but it does like to do some gardening. It digs up all the plants in my aquarium and shoves them to a corner, so I transfered the plants to another tank. I must say that Jack Dempsey is simply a very hardy fish.
I've had my jack for about 5 years. At first I had him in a tank with a good sized Green Terror and the Terror almost killed him, so I removed him from the tank and nursed him back to life. When he was large enough I reintroduced him to the tank with the Terror and everything was fine. The Terror eventually died and the tank belonged to Jack. He now lives peacefully in a tank with a Green Puffer, Scat and a small Red Pacu and he seems to like his new tank mates, even defending them against a Pike Jewel Cichlid that has been recently removed. I've had Jacks in the past and have come to know their aggressive nature well, so needless to say I am surprised how he gets along with the other fish, although I did introduce 2 Colombian sharks into the tank but Jack ate them both within 3 hours. Other than that incident I have had no problems. Aggressive or not I think it's one of the best fish for any Cichlid lover.
I hade a male jack that I grew from a baby. He was an awesome fish. He would let me pick him up out of the water and would eat out of my hand. His name was 'bad @$$' for obvious reasons. He was the king of my 200 L tank. He would poke at the convicts just to make them mad. He would scare the jewels and make them think he was going to steal their cave, but he was happy with his log to hide in. Sadly he passed away about a month ago. Well the prince of the tank is here, 'bad @$$ 2' is here to stay!
I rescued a pair of Jack Dempseys from a local pet shop because they needed a good home. Since I was 13 at the time, nobody thought I could handle them. I am now 16 and I have bred them 3 times. I have observed that my Jack Dempseys always enjoy a change and relish plants, but not for the more obvious reasons. They seem to enjoy destroying them and replanting them! Honestly, I swear they like gardening and also enjoy a bit of landscaping. So what I find they always enjoy is replanting and re-arranging the tank around for them, but this should not be done if signs of courtship are shown by the pair. People have often seen their pair of Jack Dempseys locking jaws and battling, this is a sure sign that your Jack Dempseys are going to breed and is often observed before, during and sometimes after spawning. But the male AND the female can sometimes be too rough, so always try to keep a discrete eye on them. My female Jack Dempsey had only 1/3 of her tail left when I received her. This injury was caused by the male. Jack Dempseys always prefer to spawn on a smooth piece of flat slate. Also, like most fish, Jack Dempseys can be induced to spawn by feeding them more live food and by raising the tank temperaturte a bit. With these few tips, very soon you'll have a nice happy family of Jack Dempseys 'et les' fry. But remember, the best way to breed your Jack Dempseys is to completely gain their trust, so that they will not be disturbed by you while and after spawning.
Jack's are very strong fish! I purchased 4 jack's at a pet store in Texas about 5 years ago. The pet store claimed they were Texas cichlids, but I soon learned that they were Jack Dempseys (Cichlasoma octofasciatum). A male and female paired off out of the 4 and soon were the only two left in the tank. They get very aggressive once they find a mate! About 6 months ago I moved to Iowa. I brought the two up here in a small plastic container with a battery operated air pump, they handled the journey just fine. They now live in a 100 liter aquarium and are best friends and love to do their own decorating. They have never bred, but have mating rituals often.
I have one Jack Dempsey with a green terror, a blue acara, three firemouths, a jewel cichlid, a gold severum, and a black tailed shark. He is around 15 cm, and the most gorgeous fish in my tank! Some people say they are killers, but not so with mine. He likes to show them who is boss, but he has interesting morals. I just recently added the jewel, severum, and one firemouth. The firemouth is about 3 cm long, and the severum is maybe 6 cm. He will not touch little fish. He completely ignores them, which is very lucky for the little ones. They wouldn't have a chance! However, I would be careful about what fish you put in with them, as not all are like mine. Regardless, I think it is a wonderful fish to own. They are very hardy, and very, very beautiful. If you have one in a tank with a fish big enough to challenge him, he will be incredibly colored, more so than when he is alone. Unlike others I read about, he does not dig at all, and he leaves the two plastic plants alone. They are messy eaters however, so a couple good filters are really helpful. I feed mine flakes, freeze dried bloodworms and shrimp, and frozen bloodworms. He does not like cichlid pellets, but his current diet seems to work well, as he has never gotten sick and is very active. All in all, I would recomend this fish to most people, just not beginners.